Field of the Invention
The invention pertains to the field of landscape fabric recovery. More particularly, the invention pertains to apparatus and methods for rolling and removing geotextile liners used as ground covers.
Description of Related Art
Drill pad site remediation and other geotextile liner removal operations are performed to collect used geotextile liners in a space-efficient manner to minimize transport costs and storage requirements, whether permanently in a landfill or temporarily prior to final disposition. Ideally, the geotextile liner material is ultimately transferred to a recycling facility, where the material can be either repurposed or the polymers which form the geotextile liners can be harvested and converted into plastic raw materials or articles of manufacture.
Unfortunately, conventional methods of collecting used geotextile liners are not conducive to recycling efforts. Dirt, rocks, and other debris contaminate bales of used geotextile liner material during collection or are introduced into loose shreds of the geotextile liners stored in transportable containers and interfere with and complicate recycling processes. Further, regardless of the manner of storage and transport of compressed bales of geotextile liners or loose shreds of geotextile liners in containers, the non-uniform size and shape of the geotextile shreds makes handling of the recovered geotextile liners at recycling facilities unwieldy, complicated, and expensive. Recyclers demand that geotextile liners be delivered in a relatively clean state, free of foreign matter, and in a uniform and consistent package that can, for example, be directly fed into shredding machines as a first step in recycling. Current collection methods do not meet these criteria.
Geotextile liners include a wide range of sheet or mat materials used in various applications related to oil and gas exploration, construction, landscaping, and other industries. These geotextile liners may be porous or non-porous, natural or synthetic, and include one layer or more than one layer depending on their intended use. Most notably, the oil and gas exploration industry makes extensive use of geotextile liners in various aspects of drilling operations. Environmental concerns related to spillage of drilling fluids, hydro-fracking additives, and other potentially harmful contaminants dictate that drill pads be constructed with non-porous, heavy-gauge, multi-ply geotextile liners as isolation layers with a heavy gauge plastic sheet ply between two separable felt plies that inhibit punctures from rocks or other objects above and below the geotextile liners.
Isolation layers are formed from continuous lengths of geotextile material that are unrolled from bulk rolls in overlapping strips covering an area to be protected. The overlaps are then formed into water-tight seams by various methods including heat sealing and welding the sheets of geotextile liner together to create a single monolithic layer. A typical geotextile liner may cover an area of 200,000 to 300,000 square feet after the individual sheets of geotextile liner are joined at their overlaps. Gravel, sand, or soil distributed above the now-isolated landscape provides a surface for vehicles and other machinery to move on, while chemicals potentially spilled in the area are prevented from leeching into ground water or contaminating native soils under the geotextile liners.
In other applications, geotextiles are used to form a water-tight layer at the bottom of excavations to create artificial ponds for storage of fresh water used in hydro-fracking. Artificial ponds are created for storing contaminated water and allowing natural evaporative mechanisms to return at least a part of the water to the environment without a need for treatment. Similarly, ditches are lined to channel contaminated fluids without contaminating underlying soils or aquifers. In still further applications, geotextiles are used to create temporary road beds, to protect embankments, on protective berms for soil erosion control, and for other soil management purposes.
Many jurisdictions require that oil and gas drilling sites, whether productive or not, be returned to a natural state at the completion of drilling operations. These requirements also apply to temporary ponds and other well-related structures that would potentially pose a future environmental hazard or that may be visually unappealing.
Conventional remediation practice allows geotextile liners to be buried in place. For example, pond liners are folded into the bottom of the pond excavation they line and are buried with soil previously removed from the same excavation. However, burying geotextile liners in place is not universally possible. In some cases burying geotextile liners is environmentally undesirable, because the geotextile liners may become highly contaminated with drilling fluids and other harmful substances that the geotextile liners are designed to block from seeping into underlying soils.
As a result, current best practice dictates complete removal of geotextile liners from well pad sites when drilling operations are completed. Removal of geotextile liners from a well pad site is complicated by the seamed connections that are created between sheets during the installation process. Geotextile liners are applied directly to the ground in long sheets taken from a construction vehicle holding a bulk spool of material. The finished liner after seaming may cover an area of 200,000 to 300,000 square feet, making the geotextile liner unwieldy to handle during removal and difficult to arrange in compact packages for transport to landfills or recycling facilities.
Removal of the geotextile liners therefore requires that the monolithic sheet be cut into smaller, manageable sections prior to or during collection. One conventional method of cutting geotextile liners is to use a “pizza cutter” cutting wheel designed for scoring asphalt surfaces. The cutting wheel is attached to the bucket of a front end loader or other piece of heavy construction equipment that moves across the geotextile liner and forces the cutting wheel through the geotextile liner and into the ground below. This method is not efficient, however, as soft soils under the geotextile liners allow the geotextile liners to simply sink into the earth under the cutting wheel rather than being cut by the cutting wheel. As a result, cuts are often completed manually using small knives such as gypsum cutters. In some cases, this method is completely abandoned, and the geotextile liners are torn into random shreds using a claw arm of a heavy construction vehicle.
Disposal of the geotextile liners is also difficult. In some instances, the recovered geotextile liner shreds are packed into roll-off containers or mobile garbage bins and transported to landfills. In other cases, the recovered geotextile liner shreds are placed into bailers, similar to car crushers used in scrap metal recovery, and formed into blocks. In either case, the recovered geotextile liner shreds are not only unwieldy to handle and space consumptive in landfills but also often unsuitable for recycling, because the recovery process introduces rocks, soil, and other debris into the recovered material that may complicate or preclude the recycling of the high-value polymers used to make geotextile liners.